Wire assembly machines are known. Machines alternatively known as stranders, twisters, cablers, bunchers, twiners etc . . . have been in existence for a number of years. These machines are used to combine a plurality of individual wires (or cables, strands, filaments etc . . . ) and twist them together by imparting a single, double or more twists to them, in order to produce a twisted wire. Once the twisting operation is complete, the twisted wire is taken up, deposited, wound up, payed off, etc . . . onto a rotationally driven take up spool.
Known stranding machine designs are generally characterized by the take-up spool (i.e. the spool where the final product or twisted wire is wound up, wrapped, or coiled up) being rotationally driven about its axis in order to effect, in whole or in part, the take-up of the twisted wire onto the take up spool. Once the wires have been twisted, the take up (or pay off, wounding up, wrapping up or coiling up of the take up spool) usually begins, whereby the leading end of the twisted wire is advanced onto the take up spool, which is then made to rotate by the application of rotational force.
Known machines may operate at relatively high speed, whereby the wires are advanced through the machine at relatively high speeds and the take up of the twisted wire onto the rotating take up spool is also effected at relatively high speeds. Such designs are disclosed in a number of patents, namely U.S. Pat. Nos. 4,397,141 by Gurecki, 4,599,853 by Varga-Papp, 3,791,131 by Scott, 4,182,104 by Sukle.
In accordance with known systems, the diameter and the mass of the roll of twisted wire loaded onto the take up spool changes constantly as the loading operation is progressing.
This necessitates a constantly changing energy requirement to rotate the take up spool. At the start of the loading operation, the take-up spool is empty and the wire is first deposited on the take-up spool with a low level of rotational energy required to rotate the take-up spool. As more wire is deposited, the take-up spool gradually fills, therefore gradually becoming heavier. Therefore, by the end of the loading operation, a much greater rotational force may be required to rotated the take up spool.
The rotational force required to rotate the take spool may therefore be significant. This may particularly be true near the end of the loading operation, especially for large take up spools, as the mass of all the twisted wire deposited on the take up spool has to be rotated. Thus as may be appreciated, the energy requirement necessary to rotate the take up spool may not be constant, as it may vary from the beginning of the loading operation to the end of the loading operation.
In addition, the take up spool of present machine designs may become unstable i.e. wobble, during the loading operation. The changing mass of the take-up spool coupled with the high rotational speeds of the take up spool may make it difficult to properly balance the take up spool. This is especially true for large take up spools operating at high velocity. In addition to rotating about their axis, take up spools may also themselves oscillate, for example about an axis which is off-centre. Thus present machine designs may be made which may be able to withstand wobbly, unbalanced and unstable rotating coils. In addition, present machine designs may also be able to withstand the constantly changing rotational moment of the take-up spool, from a small moment at the start of the loading operation to a potentially large moment near the end of loading operation.
In addition, during the loading operation, if an emergency braking situation occurs, the take-up spool with its varying mass may be difficult to control since the braking forces needed to be applied may vary depending on whether the take-up spool is close to empty or close to full. Braking mechanisms able to withstand large braking forces may thus be required.
Some of the operating characteristics of known machine designs may therefore require larger, heavier and more expensive parts and components to counter the large rotational moment created by a heavy mass rotating at high speed. This may therefore increase the cost of manufacture, purchase and installation of such a machine. The size of the motors or drives needed to rotationally drive the take-up spool may also be sufficiently large to rotationally drive a take up spool that will increase in size and weight during loading.
In addition, as present machine designs may be subjected to greater and changing rotational dynamic loads, they may wear out more quickly, which may increase the cost of servicing, maintaining and replacing the machines.
Machines of known design may further be designed such that the configuration of the layout of the advancing means i.e. such as a capstan member, is such that the capstan is disposed on a cradle, or is disposed such that it is itself rotated or oscillated (in addition to rotating about its own axis). As a consequence, present designs may be costly and difficult to manufacture. In addition, as the level of complexity to dispose and install the capstan in known designs may be relatively high, it is often difficult to effectively transmit power to them, which may result in loss of efficiency. In addition, the configuration of known capstan design may often require a large number of complex and costly parts and components.
In addition, the layout of the advancing means, i.e. for example the capstan member, of present machine designs may make it difficult to modify the speed of the advancing means during the loading operation, such that the operational range and efficiency of present machines may be affected.
It would therefore be advantageous to have an apparatus which would obviate the need for a rotationally driven take up spool.
It would further be advantageous to have an apparatus which would obviate the need for a capstan which is configured and disposed on an axis eccentric the axis of rotation of the apparatus.
It would therefore be advantageous to have for an apparatus which would reduce the manufacturing cost thereof. It would therefore be advantageous to have provide for an apparatus which would reduce the operating costs thereof, maintenance cost thereof.